The goal of this proposal is to secure funds to purchase a high resolution 3D X-Ray Tomography Microscope System, ZEISS Xradia 520 Versa (Carl Zeiss X-ray Microscopy Inc, formerly Xradia, Inc), equipped with a high speed workstation and analysis software. The addition of ZEISS Xradia 520 Versa at USC will facilitate the research of many of our investigators whose projects are aimed at understanding the processes that govern dental, bone, and heart development with a focus on developing novel tissue regeneration methods for fixing oro- and cranio-facial defects and improved understanding of bone remodeling for skeletal regeneration. In this proposal we highlight how the various features of the requested unit will enhance/aid the research of our users, with respect to their currently funded NIH research programs or in some cases, provide additional research capabilities. X-ray based 3D imaging has allowed investigators to quantify traits of attenuating biological tissues with a high degree of accuracy and precision in a non-destructive manner. Many of the bone and cardiovascular traits needed to advance our understanding of the pathogenesis of disease (heart disease, osteoporosis) are derived from the spatial distribution of structures (vessels, trabeculae) and are thus unique to 3D images. These traits cannot be readily determined from 2D images, unless one painstakingly reconstructs serial histological sections into a 3D stack. These histological studies are rare due to the prohibitively expensive cost and tremendous effort involved in generating and reconstructing the sections The addition of this system will strengthen ongoing work in engineering, dentistry, developmental biology, and genetic medicine by current users of the USC Molecular Imaging Center (MIC), as well as greatly enhance the ability of the Center to support new research in oncology, cardiology, pathology, material sciences, and developmental biology. We have gathered 15 NIH funded investigators (11 major and 4 minor users) with research disciplines in medicine, oncology, dentistry, pharmaceutical sciences, neurosciences, genetic medicine, engineering, stem cell, and developmental biology to support our current S10 application.